U.S. Pat. No. 6,570,141 B2 discloses a variable width transverse flux coil that includes moveable sections of the coil that are connected to a power supply. Such an arrangement requires flexible power connections between the coil sections and power supply, and requires moveable assemblies that are large since their lengths are directly related to the maximum width of the strip to be heated, and, as a consequence, are heavy, particularly if they include magnetic flux concentrators.
It is one object of the present invention to provide a transverse flux electric induction coil comprising a fixed powered coil section and one or more moveable passive coil sections that provide a convenient means for adjusting the width of the coil to the width of an electrically conductive workpiece that is to be inductively heated.
It is another object of the present invention to provide a transverse flux electric induction coil comprising a fixed powered coil section and one or more moveable passive coil sections that provide a convenient means for adjusting a transverse end, or ends of the coil if the position of the electrically conductive workpiece being inductively heated wanders, or weaves, in the transverse direction during the heating process. The moveable passive coil sections can be substantially shorter than the width of the electrically conductive workpiece. Consequently they are lightweight and can easily be moved to track the instantaneous positions of the opposing edges of the electrically conductive workpieces.